1. Field of the Invention
The present invention relates to a display device including a light-emitting element. Moreover, the invention relates to an electronic device using a display device including a light-emitting element.
2. Description of the Related Art
In recent years, display devices including light-emitting elements typified by EL (Electro Luminescence) elements have been developed, and wide applications thereof are expected because of utilizing the advantages such as high image quality, wide viewing angle, thin shape, and lightweight of a self-light emission type. Luminance of a light-emitting element is proportional to a current value of the light-emitting element.
A light-emitting element has a property that a resistance value is decreased when ambient temperature (hereinafter, also referred to as environmental temperature) becomes high and a resistance value is increased when ambient temperature becomes low, and a property that a resistance value is increased by a change with time. Thus, there is a display device which suppresses an influence of fluctuation in a resistance value of a light-emitting element due to a change in environmental temperature and a change with time (for example, refer to Patent Document 1: Japanese Patent Laid-Open No. 2002-333861).
The display device in Patent Document 1 has a light-emitting element, a monitoring light-emitting element, a constant current source, and a buffer amplifier. A constant current is supplied from the constant current source to the monitoring light-emitting element. One of a plurality of electrodes of the monitoring light-emitting element is connected to one of a plurality of electrodes of the light-emitting element through the buffer amplifier. In this state, if the change in environment temperature and change with time occur, an electric potential of said one of the plurality of electrodes of the monitoring light-emitting element is changed, and this electric potential is transmitted to an electric potential of said one of the plurality of electrodes of the light-emitting element. By changing an electric potential of one of the plurality of electrodes of a light-emitting element depending on the change in environment temperature and change with time in this manner, an influence of fluctuation in resistance value of the light-emitting element can be suppressed.